Metformin may help some people with type 1 diabetes use less insulin

A new trial found that metformin helped adults with type 1 diabetes use about 12% less insulin while keeping blood sugar levels stable.The expected benefit did not appear to come from improved insulin resistance, which surprised the researchers.The study was small, so metformin is not suddenly a standard add-on treatment for type 1 diabetes, but the findings are important enough to investigate further.

A new clinical trial suggests metformin may still have a role in type 1 diabetes, even if not for the reason many had assumed.

Doctors have sometimes prescribed metformin off-label in type 1 diabetes in the hope that it would improve insulin resistance.

This study found that it did not do that.

But it did show something else that could still matter a great deal to patients.

Adults taking metformin used about 12% less insulin than those taking placebo, while keeping blood sugar control broadly stable.

That is a meaningful finding.

For people with type 1 diabetes, insulin is lifesaving, but it also brings a heavy day-to-day burden.

Anything that safely reduces the amount needed could make management a bit easier.

The trial involved 40 adults with long-standing type 1 diabetes.

Participants were randomised to take either metformin or placebo for six months.

Researchers then used detailed metabolic testing, including clamp studies, to assess insulin resistance in different parts of the body.

They found no clear improvement in insulin resistance and no major change in glucose control.

So the expected mechanism did not hold up.

That is what makes the study interesting.

Metformin seems to be doing something useful, but not in the way researchers thought.

The team now suspects the gut may be involved.

There is growing evidence that metformin acts partly through the gut microbiome, and the researchers are now exploring whether changes in gut bacteria could explain the lower insulin requirement.

That is plausible, but it remains a theory for now.

The study should also be kept in proportion.

It was small and lasted 26 weeks, so it does not settle the question of whether metformin should be used routinely in type 1 diabetes.

It also does not mean everyone with type 1 diabetes will benefit.

Still, it is a solid and interesting result.

Metformin is cheap, widely available and well known, and if future research confirms that it can safely reduce insulin needs for some people with type 1 diabetes, that could be genuinely useful.